Artificial knee-joint.



0. A. AUNGER.

ARTIFICIAL KNEE JOINT.

APPLICATION FILED APILZ, 1913.

Patented Sept. 30, 1913.

2 SHEETS-SHEET 1.

G. A. AUNGER.

ARTIFICIAL KNEE JOINT.

APPLIOATION FILED APR.2, 191s.

Patented Sept. 30, 1913.

2 SHEETS-SHEET 2.

I H5555 mafia CLYDE A. AUNGER, or SAN FRANCISCO, CALIFORNIA.

ARTIFICIAL KNEEJOINT.

Specification of Letters Patent.

Patented Sept. 30, 1913.

Serial No. 758,704.

Application filed April 2, 1913.

To all whom it may concern:

Be it known that I, CLYDE A. A NGER, a citizen of the United States,residing in the city and county of San Francisco and State ofCalifornia, have invented a new and useful Improvement'in ArtificialKnee-Joints, of which the following is a specification.

My invention relates to artificial knee joints wherein a leg-portion ispivotally secured to a stump portion, the said leg portion beingoperated by a supporting suspender attached to aback check which in turncontrols the forward movement of the said legportion and the object ofmy invention is to provide improved means that shall be simple ofconstruction and operation and adapted to operate in conjunction withthe supporting suspender for the purpose of controlling the forwardmovement of the leg portion. i

F ora full and clear comprehension of my invention reference should behad to the drawings forming a part of this specification wherein likenumerals of reference designate similar parts throughout the saidspecifications and drawings and in which- Figure 1 is a side elevationof an artificial leg and suspenders the lower part of the leg portionbeing broken away. Fig. 2 is a front elevation of Fig. 1. Fig. 3 is abroken rear view of the stump portion showing the mannor in which thesuspenders are secured thereto. Fig. 1 is an enlarged broken sectionalview of the knee joint in a standing or vertical position. Fig. 5 is asimilar view showing the position of the several parts when the knee isbent as in a sitting position. Fig. 6 is a broken rear view of the kneejoint in elevation.

My invention consists mainly of a hollow stump portion 1 which isadapted to receive the stump of an amputated leg where the limb has beenamputated above the knee. A leg portion 2 is pivotally secured to thestump portion 1 by means of the knee bolt 3, the said knee bolt 3 beingrigidly secured at each end thereof to vertical extensions on the upperportion of the leg 2. Aback check 4, having an upper vertical ofisetportion 4 and a central horizontal portion 6, is rigidly secured to theupper back portion of the leg' 2, the upper vertical portion 1 of thesaid back check 4 rest-ing against the knee bolt 3 within the hollowstump 1.

- A strap .5 is secured to the horizontal portion 6 of the back check4:, and after passing over a roller 7, that is rotatably mounted withina horizontal slot 8 within the front wall of the stump 1, and under aretaining strap 10, is secured to the front lower ends of two supportingsuspenders 9 that pass over the shoulders of the wearer and are securedto the back portion of the stump 1 as illustrated in Fig. 3 of thedrawings. The retaining strap 10 is secured to and encircles the top ofthe stump l for the purpose of strengthening that member and also forthe purpose of retaining the check strap 5 againstthe stump 1. A slot 12is provided in the lower back portion of the stump 1 for the receptionof the back check t. The lower end of the slot 12 is padded as at 14with felt or any other suitable shock absorbing material.

By referring to Fig. 4: it will be observed that when the leg 2 isplanted firmly on the ground it will serve as a support for the stump 1.The stump 1 will be prevented from rotating forward on the knee joint 3by the back checkt against which the padded endll. of the slot 12 in thestump 1 is resting. It is apparent from the foregoing description thatwhile the leg portion 2 is free to swing backward on the knee bolt 3when the said leg is raisedfrom the ground it is prevented from swingingforward from the position shown in Fig. 4 by the back check 4.

The operation of the artificial knee joint in walking is as follows: owill assume, for purposes of illustration, that the right leg is the onethat has been replaced by the artificial limb. In taking a step forwardwith the left leg the weight of the body of the wearer is supported bythe artificial right leg, the foot of which is planted firmly on theground. As the body bends forward in stepping out with the left leg theweight of the body is brought forward of the knee joint, andconsequently of the knee bolt 3, of the artificial right leg. Instepping out with the left leg the tendency of the stump l of the rightleg is to rotate forward upon the knee bolt 3 which would precipitatethe wearer forward if it were not checked by the padded end 14 of theslot 12 through which the back check 4 projects. When the step forwardwith the left foot is finished and the weight of the body transferredthereto V the next actionin walking would be to bring of the right leg,

the artificial right leg forward. As the right leg is raised from theground and the stump portion 1 is brought forward by the stump the leg 2is raised-from'the ground andgis,"consequently, free to swing forwardoni'the knee bolt 3. This forward movement of -tlzlie leg 2 iscontrolled and facilitated by means of the suspen'ders9 which pass overthe shoulder of the wearer and are secured to the strap 5, the saidstrap being inturn secured to thehorizontal' portion 6 of the'back check4.- The forward movementis" accomplishedby giving a slight forwardmotion to one of the shoulders-which motion is communicated, by means ofthe straps 9 and 5 and the-back check 4, to the leg 2 so that the saidleg 2 may be brought forward with a speed 'directly proportionate to themovement of the shoulder. In this manner a movement simulating themotion of astep of a natural limb is accomplished. The above describedforward movement of the right leg 2 is stopped at the proper moment andin the proper position to receive the weight of the body of the wearerfor the next step with the left leg by the back check 4 which comes incontact with the padded end of the slot 12.

c It is apparent that in walking" the leg 2 5 is-always under controland'may be brought I claimaasnew and desirerto secure by Letters Patentis An artificial knee joint comprising a leg portion having verticalextensions secured to each side of the upper end thereof; a knee boltrigidly secured between the upper ends of the vertical extensions; astump'port-ion pivotally secured to the kneebolt and hav ingahorizontal'slot with a roller therein in "the" front portion, and avertical slot with a padded lower end in the back thereof; a

retaining strap secured to and encircling the upper portionzof thestump; a back check comprising upper and lower vertical por tionsand' acentral'horizontal portion; the lower vertical: portion being rigidlys'e-. cured to: the back of theleg portion and adapted .to' engage thelower paddedend of the vertical slot in the back of therstump and theupper vertical portion being adapted to engage'the'knee bolt within thehollow stump; a strapv secured: to the horizontal portion of thebackcheck and adapted/to r I pass over' the roller in the horizontal slot inthe front portion of the-stump and under theiretaining strap securedtothe upper portion of the. said stump;.,and'shoulder straps secured tothe back of the stump and-adaptedito' passvover theshoulder of thewearer and to engage the upper end of thefstrap see cured-to thehorizontal: portion of therback check;

In witness whereof I hereuntoset my witnesses. a

' CLYDE A1 AUNGERQ WVitnesses: i

ARTHUR WHITE, JAMnsF. MQGUE;

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